1. Field of the Invention
The present invention relates to an antenna apparatus for a vehicle, which is disposed on a window glass of a vehicle.
2. Prior Art
When a radio receiver, television receiver, or vehicle telephone set is installed in a vehicle to receive a radio or television broadcast signal or to communicate with a person outside the vehicle, a special-purpose antenna adjusted to a specific frequency band to be used must be mounted on the vehicle. For example, a rear pole antenna or a glass print antenna is mounted on the vehicle as an antenna for a vehicle telephone band. The rear pole antenna has a rod-like conductor of a length corresponding to the vehicle telephone band. The rod projects on the rear portion of the vehicle body. The glass print antenna is formed by printing and baking a conductive paste on the window glass of the vehicle to have a loop or semi-loop shape corresponding to the wavelength of the vehicle telephone band.
Since the rear pole antenna projects from the vehicle, this impairs the outer appearance of the vehicle. Mounting of the antenna is so cumbersome that a user cannot easily mount the rear pole antenna. The rear pole antenna sometimes disturbs washing of the vehicle.
In contrast to this, since the glass print antenna is provided on the surface of the window glass of the vehicle, the above drawbacks are not caused. However, since the conductive paste is printed and baked on the surface of the window glass of the vehicle, it cannot be easily mounted. The glass print antenna is normally provided on the surface of the rear window glass. However, heater wires for defogging the surface are often also arranged on the rear window glass. For this reason, the position and area where the glass print antenna is arranged are limited, and the position and area for obtaining good antenna performance cannot be desirably selected.